I finally got the chance to provide dedicated lighting for the layout - two spot lights and two lamp sheds. the light simulates bright day light and can be switched to Morning/Evening mode by switching off the spot lights.
Here are some photos of the whole layout. The space below the layout has been made into a storage place for all stuff related to model railroading! :)
And now here are some photos of the layout after it's operational once again. My personal take is, the lighting efforts have paid out!